Which domain includes well-known pathogenic organisms?

$A$ ball of mass $2\;kg$ and another of mass $4\;kg$ are dropped together from a $60\;ft$ tall building. After a fall of $30\;ft$ each towards the Earth,their respective kinetic energies will be in the ratio of?

How is red phosphorus obtained from white phosphorus?

If $\theta$ is the angle between the lines $x^2+2 h x y+b y^2=0$,then the angle between $x^2+2 x y \sec \theta+y^2=0$ is

Calculate the surface temperature of the planet,if the energy radiated by unit area in unit time is $5.67 \times 10^4 \, W$. (Assume the planet is a black body).

The difference between the $n^{\text{th}}$ and $(n+1)^{\text{th}}$ Bohr's radius of a hydrogen atom is equal to the $(n-1)^{\text{th}}$ Bohr's radius. The value of $n$ is: